Automatic control of internal combustion engines



Nov. 5, 1940. J. OBERHOLLENZ'ER AUTOMATIC CONTROL OF INTERNAL COMBUSTION ENGINES Filed Aug. 30, 1939 INVENTOR JOSEPH OBERHOLLENZER 1 AITORNE'Y Patented Nov. 5, 1940.

AUTOMATIC CONTROL or INTERNAL COMBUSTION ENcmEs Joseph Oberhollenzer, Jackson Heights, N; Y., as-

.slgnor to Power Patents Company, Hillside,

N. J a corporation of Maine I 1 Application August so, 19 9, Serial sofzsasss 5Claims. (01. 123-97) This invention relates generally to the control of internal combustion engines, and is more particularly directed to improvements in apparatus for efiecting automatic deceleration control of 6 internal combustion engine prime movers and of vehicles or other devices powered thereby.

The primary object of the invention is to provide apparatus which shall operate automatically in response to a drop in pressure in the intake 10 manifold of an internal combustion engine below the normal idling intake pressure to retard or interrupt discharge of intake exhaust gases to atmosphere and to thereby build up a back pressure which is effective to reduce consumption of lubricating oil and to increase the gas compression resistance to the piston exhaust stroke during deceleration.

A more particular object of the invention is to provide an improved automatic deceleration control apparatus which is simple and economical both to install and to operate. g

In the operation of internal combustion engines at idling speed, relatively high vacuum is developed in the intake manifold, and this vacuum is reduced during periods of acceleration. However, during periodsof deceleration at engine speeds above the normal idling speed, a high degree of vacuum builds up in the intake manifold, and this high vacuum results in excessive consumption of lubricating oil, as well as in exhaust smoke and often back firing. A feature of the apparatus which is hereinafter described is that it embodies means for utilizing this high vacuum which is developed in the intake manifold during periods of deceleration at high speed, both to actuate a valve so mounted as to interrupt free discharge of engine exhaust gases to atmosphere, and also for initiating through sensitive pressure responsive mechanism the operation of the valve actuating means.

With the aforementioned and other objects and features in view, the invention consists in the improved apparatus for controlling internal combustion engine operation which is hereinafter described and more particularly defined in the accompanying claims.

The invention will be hereinafter described more specifically by reference to the accompanying drawing, which is a diagrammatic view in elevation, with parts shown in section, of a preferred embodiment of the improved deceleration control apparatus shown in operative relation with the intake and exhaust manifolds of an internal combustion engine.

Referring to the drawing, numeral I0 designates the exhaust manifold andnumeral i2 the intake manifold of an internal combustion engine with which the control apparatus of the present invention is operatively connected. Numeral it designates a poppet valve having a stem I5 which is slidably journaled in the longitudinal axis of manifold iii. 'A multi-apertured bearing support l6 for valve stem I5 is provided with a tubular extension ll having at its top an inward taper forming an annular seat It for the valve it. With the valve it in itsnormal open position (as illustrated) gas exhausted from the internal combustion engine flows through manifold ill and' through apertures 20 of the valve supporting member it in the direction indicated by the arrows. V

Reciprocal movement oiithe valve it toward and away from its seat i8 is produced by rotation of a cam 22 having its edge or operating surface mounted in aligned contact with the lower end of valve stem 55. Cam 22 is keyed to a shaft 23, and a crank 24 is also keyed to shaft 23 at one end thereof. Actuating mechanism for the crank includes a piston 25 which is reciprocably mounted within a cylinder 28. The piston is connected to the crank 24 by a piston rod 29 and a connecting rod Bil. A retractile spring 32 is attached to connecting rod 30 in position to normally hold the crank, cam, piston and valve it in the position illustrated, allowing free discharge of engine exhaust gases to atmosphere through the mamfold ill.

For the purpose of actuating piston 26 in cylinder 28 a valve 345 is provided having a pair of fluid intake and exhaust ports, one of which is connected by a conduit 36 to the right hand end of cylinder 28 (as viewed in the drawing), while the other port of valve 3% is connected by a conduit 38 t to rotate cam 22 in clockwise direction to close valve M, thereby interrupting discharge of engine exhaust gases to atmosphere and building up a back pressure in the exhaust pipe iii and in the engine cylinders (not shown) thereby retarding rotation of the engine crank shaft.

An essential and important feature of the present invention is that of providing means which shall be responsive to variations in vacuum within the intake manifold i2 within a narrow range, for controlling the operation of valve 34. be appreciated that mechanism such as the piston 26 and cylinder 28 for actuating valve l4 in the exhaust manifold, would not have suificient sensitivity to be practically useful for limiting, within a narrow range of relatively high vacuum in theintake manifold, the periods during which disehargeof engine exhaust gases to atmosphere shall be interrupted. Essentially the mechanism provided for controlling operation of valve 34 includes an adjustable flexible diaphragm unit 40 which is mounted within a casing and one side of which is communicably connected with the interior of manifold i2 by a pipe 42. To the other side of diaphragm 40 there is operatively connected a plunger 43 under the control of a retractile spring 44. The tension of spring 44 can be adjusted by a nut '45 threadably engaging plunger 43, so that the diaphragm will only operate in response to a vacuum which is somewhat greater than that developed in the intake manifold at idling speed, (for example a vacuum exceeding 19 inches of mercury). To the end of plunger 43 there is attached a stem 46 which is in turn connected to an end of a crank arm 41. Crank arm 41 is pivoted at its other end on a pin 48 which is supported by a bracket 49 mounted on the casing of valve 34. An actuating stem 58 for valve 34 is operatively connected to the crank arm 41 for reciprocal movement by the crank arm in response to any corresponding movement of the diaphragm 48.

When a vacuum is developed in the intake manifold i 2 which exceeds by a predetermined amount the vacuum normally existing in the manifold during the period when the engine is operating at idling speed, diaphragm 40 moves downwardly carrying therewith the unpivoted end of crank 41, and this movement eflects corresponding downward movement of stem 58, causing valve 34 to open. As soon as valve 34 opens, communication is established between manifold i2 and the interior of cylinder 28, causing piston 28 to move to the right to close valve l4.

When .the vacuum in t e intake manifold drops below that predetermined amount at which diaphragm 40 is adjusted to operate, the spring 44 will move the diaphragm and the free end of crank 41 upwardly sufliciently to close valve 34, thus interrupting communication between the cylinder 28 and the intake manifold, while at the same time establishing communication between cylinder 28 and an air intake aperture 52 in the wall of valve 34. This communication is established through the lower chamber 54 of valve 34 and through a lateral port 58 and an axial bore 51 in the lower part of valve stem 50, which, with the valve in its closed position, brings an annular groove 58 in the valve stem in communicable relation respectively with bore 51 and withair intake aperture 52. Thus with valve 34 closed atmospheric air-pressure is applied to the right hand end of piston 28, wlththe result that the retractile spring 32 is enabled to pull the pise ton 28 to the left hand end of cylinder 28, thereby bringing valve I4 to its normally open position illustrated.

In order to prevent the development of too high back pressure within exhaust pipe 10 on the upstream side of valve l4 during the period when the valve is closed, a pressure relief valve 60 is provided which is adjustable by means of a It will screw adJustment 82 to release excess pressure within the exhaust pipe whenever such pressure tends to exceed a predetermined safe value. The intake side of valve is operatively connected to-exhaust pipe "I on the upstream side of valve 5 H, by a pipe 84; and the discharge side of valve 68 is operatively connected to the pipe ID on the downstream side of valve l4 by a pipe 85.

If it be assumed, for example, that the control apparatus of the present invention is to be used 10 with an engine which develops a maximum vacuum in the intake manifold of about 19 inches of mercury at idling speed, then the diaphragm 40 may be adjusted for opening valve 34 whenever the vacuum in the intake manifold l2 ex- 15 ceeds, for example, 19 /2 inches of mercury. Thus whenever the engine is operating at a speed above idling speed and is decelerating, the vacuum in the intake manifold increases above that at which the diaphragm 48 is set to actuate valve 20 34, thereby opening this valve and communicably connecting the intake manifold with the cylinder 28. Piston 28 is thus drawn to the right against the pullof spring 32, thereby closing the valve l4. This valve will remain closed as 25 long as the engine is decelerating at a speed developing a vacuum above the idling vacuum in the intake manifold. When the vacuum in the intake manifold drops below that developed at idling speed, diaphragm 48 is moved upwardly 30 under the action of spring 44, thereby closing valve 34 and at the same time opening communication between cylinder 28 and air aperture 52. Atmospheric pressure is thereby built up in chamber 28 at the right hand of piston 26, per- 35 mitting spring 22 to move the piston toward the left to open valve I4.

Having thus described the preferred form of the invention, what is claimed as new is:

1. Control apparatus for internal combustion 4 engines comprising, an exhaust discharge pipe for waste engine combustion gases, a valve mounted in said pipe for controlling discharge of gases therethrough to atmosphere, an intake pipe for delivering air and fuel to the engine, means operable by variations in gas pressure for actuating said valve, a conduit connecting said means with the intake pipe, 9. second valve in said conduit controlling communication between said valve actuating means and the intake pipe, 50 a device operable by variations in gas pressure for actuating said second valve, and a conduit connecting said device with the intake pipe.

2. Apparatus as defined in claim 1 in which said device is adjustable for operation to open 55 said valve only in response to a vacuum in said intake pipe greater than that existing therein when the engine is idling.

3. Apparatus as defined in claim 1 together with a pressure-relief valve having its intake on operatively connected to the discharge pipe on the upstream side of the valve and having its exhaust side communicably connected with the exhaust pipe on the downstream side of the valve.

4. Control apparatus for internal combustion engines comprising, an exhaust discharge pipe for waste engine combustion gases, an apertured valve supporting and seating member mounted transversely in said exhaust pipe, a valve mounted on said member in position to completely in- 70 terrupt discharge of engine exhaust gases to atmosphere when seated, an intake pipe for delivering air and fuel to the engine, means operable by variations in gas pressure for actuating said valve, a conduit connecting said means with the 75 intake pipe, a second valve mounted in said conduit in position to control communication between said valve actuating means and the intake pipe, means operably associated with said second valve for establishing communication between the valve actuating means and atmosphere during periods when said second valve cuts ofi communication between the valve actuating means and the intake pipe, an adjustable gas pressure sensitive device for actuating said second valve, and a communicable connection between said device and the intake pipe.

5. Control apparatus for internal combustion engines comprising, an exhaust discharge pipe for waste engine combustion gases, a valve mounted in said pipe for controlling discharge of gases therethrough to atmosphere, an intake pipe for delivering air and fuel to the engine, and means for actuating said valve, said means including an element normally holding said valve in open position, a device operable by variations in gas pressure, and. a conduit connecting said device with the intake pipe, said device being adjustable for operation to effect closing of said valve only in response to a vacuum in said intake pipe greater than that existing therein when the engine is idling.

JOSEPH OBERHOLLENZER. 

